object.c

   1 #include "cache.h"
   2 #include "object.h"
   3 #include "blob.h"
   4 #include "tree.h"
   5 #include "commit.h"
   6 #include "tag.h"
   7
   8 static struct object **obj_hash;
   9 static int nr_objs, obj_hash_size;
  10
  11 unsigned int get_max_object_index(void)
  12 {
  13         return obj_hash_size;
  14 }
  15
  16 struct object *get_indexed_object(unsigned int idx)
  17 {
  18         return obj_hash[idx];
  19 }
  20
  21 const char *type_names[] = {
  22         "none", "blob", "tree", "commit", "bad"
  23 };
  24
  25 static unsigned int hash_obj(struct object *obj, unsigned int n)
  26 {
  27         unsigned int hash = *(unsigned int *)obj->sha1;
  28         return hash % n;
  29 }
  30
  31 static void insert_obj_hash(struct object *obj, struct object **hash, unsigned int size)
  32 {
  33         int j = hash_obj(obj, size);
  34
  35         while (hash[j]) {
  36                 j++;
  37                 if (j >= size)
  38                         j = 0;
  39         }
  40         hash[j] = obj;
  41 }
  42
  43 static int hashtable_index(const unsigned char *sha1)
  44 {
  45         unsigned int i;
  46         memcpy(&i, sha1, sizeof(unsigned int));
  47         return (int)(i % obj_hash_size);
  48 }
  49
  50 struct object *lookup_object(const unsigned char *sha1)
  51 {
  52         int i;
  53         struct object *obj;
  54
  55         if (!obj_hash)
  56                 return NULL;
  57
  58         i = hashtable_index(sha1);
  59         while ((obj = obj_hash[i]) != NULL) {
  60                 if (!memcmp(sha1, obj->sha1, 20))
  61                         break;
  62                 i++;
  63                 if (i == obj_hash_size)
  64                         i = 0;
  65         }
  66         return obj;
  67 }
  68
  69 static void grow_object_hash(void)
  70 {
  71         int i;
  72         int new_hash_size = obj_hash_size < 32 ? 32 : 2 * obj_hash_size;
  73         struct object **new_hash;
  74
  75         new_hash = calloc(new_hash_size, sizeof(struct object *));
  76         for (i = 0; i < obj_hash_size; i++) {
  77                 struct object *obj = obj_hash[i];
  78                 if (!obj)
  79                         continue;
  80                 insert_obj_hash(obj, new_hash, new_hash_size);
  81         }
  82         free(obj_hash);
  83         obj_hash = new_hash;
  84         obj_hash_size = new_hash_size;
  85 }
  86
  87 void created_object(const unsigned char *sha1, struct object *obj)
  88 {
  89         obj->parsed = 0;
  90         obj->used = 0;
  91         obj->type = TYPE_NONE;
  92         obj->flags = 0;
  93         memcpy(obj->sha1, sha1, 20);
  94
  95         if (obj_hash_size - 1 <= nr_objs * 2)
  96                 grow_object_hash();
  97
  98         insert_obj_hash(obj, obj_hash, obj_hash_size);
  99         nr_objs++;
 100 }
 101
 102 struct object *lookup_object_type(const unsigned char *sha1, const char *type)
 103 {
 104         if (!type) {
 105                 return lookup_unknown_object(sha1);
 106         } else if (!strcmp(type, blob_type)) {
 107                 return &lookup_blob(sha1)->object;
 108         } else if (!strcmp(type, tree_type)) {
 109                 return &lookup_tree(sha1)->object;
 110         } else if (!strcmp(type, commit_type)) {
 111                 return &lookup_commit(sha1)->object;
 112         } else if (!strcmp(type, tag_type)) {
 113                 return &lookup_tag(sha1)->object;
 114         } else {
 115                 error("Unknown type %s", type);
 116                 return NULL;
 117         }
 118 }
 119
 120 union any_object {
 121         struct object object;
 122         struct commit commit;
 123         struct tree tree;
 124         struct blob blob;
 125         struct tag tag;
 126 };
 127
 128 struct object *lookup_unknown_object(const unsigned char *sha1)
 129 {
 130         struct object *obj = lookup_object(sha1);
 131         if (!obj) {
 132                 union any_object *ret = xcalloc(1, sizeof(*ret));
 133                 created_object(sha1, &ret->object);
 134                 ret->object.type = TYPE_NONE;
 135                 return &ret->object;
 136         }
 137         return obj;
 138 }
 139
 140 struct object *parse_object(const unsigned char *sha1)
 141 {
 142         unsigned long size;
 143         char type[20];
 144         void *buffer = read_sha1_file(sha1, type, &size);
 145         if (buffer) {
 146                 struct object *obj;
 147                 if (check_sha1_signature(sha1, buffer, size, type) < 0)
 148                         printf("sha1 mismatch %s\n", sha1_to_hex(sha1));
 149                 if (!strcmp(type, blob_type)) {
 150                         struct blob *blob = lookup_blob(sha1);
 151                         parse_blob_buffer(blob, buffer, size);
 152                         obj = &blob->object;
 153                 } else if (!strcmp(type, tree_type)) {
 154                         struct tree *tree = lookup_tree(sha1);
 155                         obj = &tree->object;
 156                         if (!tree->object.parsed) {
 157                                 parse_tree_buffer(tree, buffer, size);
 158                                 buffer = NULL;
 159                         }
 160                 } else if (!strcmp(type, commit_type)) {
 161                         struct commit *commit = lookup_commit(sha1);
 162                         parse_commit_buffer(commit, buffer, size);
 163                         if (!commit->buffer) {
 164                                 commit->buffer = buffer;
 165                                 buffer = NULL;
 166                         }
 167                         obj = &commit->object;
 168                 } else if (!strcmp(type, tag_type)) {
 169                         struct tag *tag = lookup_tag(sha1);
 170                         parse_tag_buffer(tag, buffer, size);
 171                         obj = &tag->object;
 172                 } else {
 173                         obj = NULL;
 174                 }
 175                 free(buffer);
 176                 return obj;
 177         }
 178         return NULL;
 179 }
 180
 181 struct object_list *object_list_insert(struct object *item,
 182                                        struct object_list **list_p)
 183 {
 184         struct object_list *new_list = xmalloc(sizeof(struct object_list));
 185         new_list->item = item;
 186         new_list->next = *list_p;
 187         *list_p = new_list;
 188         return new_list;
 189 }
 190
 191 void object_list_append(struct object *item,
 192                         struct object_list **list_p)
 193 {
 194         while (*list_p) {
 195                 list_p = &((*list_p)->next);
 196         }
 197         *list_p = xmalloc(sizeof(struct object_list));
 198         (*list_p)->next = NULL;
 199         (*list_p)->item = item;
 200 }
 201
 202 unsigned object_list_length(struct object_list *list)
 203 {
 204         unsigned ret = 0;
 205         while (list) {
 206                 list = list->next;
 207                 ret++;
 208         }
 209         return ret;
 210 }
 211
 212 int object_list_contains(struct object_list *list, struct object *obj)
 213 {
 214         while (list) {
 215                 if (list->item == obj)
 216                         return 1;
 217                 list = list->next;
 218         }
 219         return 0;
 220 }
 221
 222 void add_object_array(struct object *obj, const char *name, struct object_array *array)
 223 {
 224         unsigned nr = array->nr;
 225         unsigned alloc = array->alloc;
 226         struct object_array_entry *objects = array->objects;
 227
 228         if (nr >= alloc) {
 229                 alloc = (alloc + 32) * 2;
 230                 objects = xrealloc(objects, alloc * sizeof(*objects));
 231                 array->alloc = alloc;
 232                 array->objects = objects;
 233         }
 234         objects[nr].item = obj;
 235         objects[nr].name = name;
 236         array->nr = ++nr;
 237 }